1. Field of the Invention
The present invention relates to a production method and a production apparatus for a rotor which is produced by combining a slot insulator and a coil bar to a rotor core.
2. Description of Related Art
Japanese Patent Application No. 7-326983 (U.S. Pat. No. 5,778,512) discloses a method of integrating or assembling coil bars (lower layer coil bars and upper layer coil bars) each in a channel-like shape having a linear coil trunk and a pair of coil arms and slot insulators (lower layer slot insulators and upper layer slot insulators) for insulating the coil trunks inserted into slots of a rotor (armature) core from the armature core, to the armature core.
However, according to the above integrating method, there poses the following problem in order to insert the coil trunks of the coil bars into the slots after inserting the slot insulators into the slots of the armature core.
That is, the slot insulators are not positioned in the axial direction in respect of the slots of the armature core and therefore, the slot insulators may be shifted in the axial direction in the slots. In this case, for example, in respect of the lower layer slot insulator, the length in the axial direction is substantially equal to the length of the slot (length of armature core in the axial direction) plus a thickness of a pair of disk-like inner side insulators and therefore, when the lower layer slot insulator is shifted in the axial direction at inside of the slot, one end of the lower layer slot insulator is projected from either of end faces of the pair of disk-like inner side insulators arranged at both end faces of the armature core. When the lower layer coil bar is made to be inserted into the slot under this state, as shown in FIG. 46, a coil trunk 8b of a lower layer coil bar 8 may interfere with the projected one end of the lower layer slot insulator 4 and a coil arm 8a may not be inserted into a slot 3a with certainty.
Particularly, when the length of the lower layer slot insulator in the axial direction is set to be slightly larger than the length of the lower layer coil trunk, the influence by the shift of the lower layer slot insulator in the axial direction becomes significant. As a result, when, for example, the lower layer slot insulator is produced by a soft material in a thin film shape, it is conceivable that the lower layer slot insulator may be deformed or destructed easily by the interference with the coil arm.
Further, when the slot insulator is integrated to shift in the axial direction in respect of the slot, although one end of the slot insulator in the axial direction is projected from the end face of the armature core, the other end of the slot insulator is recessed from the end face of the armature core and therefore, the wall face of the slot is exposed and the insulation in respect of the coil trunk cannot be ensured.
Further, although a method of positioning the slot insulator in the axial direction in respect of the slot by arranging a positioning member on the side of the end face of the armature core and bringing one end of the slot insulator in contact with the positioning member, is possible, when the slot insulator is produced by a soft material in a thin film shape, the rigidity of the slot insulator is deficient and therefore, the accurate positioning may not be carried out since the side of the one end of the slot insulator which is brought into contact with the positioning member is deformed. When the coil trunk is inserted into the slot under this state, the coil arm interferes with the deformed portion of the slot insulator and the coil trunk cannot be integrated into the slot with certainty. Further, when the slot insulator is shifted in the axial direction in accordance with the deformation of the one end side, the other end side of the slot insulator is recessed into the slot and the wall face of the slot is exposed and therefore, the coil trunk may not be insulated from the armature core with certainty.
It is an object of the present invention to provide a production method and a production apparatus for a rotor capable of integrating a slot insulator and a coil bar with certainty without causing deformation or destruction of the slot insulator in integrating the coil bar to a rotor core.
It is a further object of the present invention to provide a production method for a rotor of a rotating electric machine capable of reducing bonding portions of coil bars and facilitating integration of the coil bars to a rotor core.
According to one aspect of the present invention, slot insulators and coil trunks are previously combined before insertion into an armature core and the combined sets of slot insulators and coil bars are integrally inserted into slots from outer peripheral side in the radial direction of the armature core to thereby integrate to the armature core. According to the method, the slot insulators are inserted into the slots integrally with the coil bars and therefore, the slot insulators are prevented from being positionally shifted in the axial direction in respect of the slots and the slot insulators and the coil bars can be integrated to the armature core with certainty.
According to another aspect of the present invention, the slot insulator is provided with a section in a channel-like shape comprising a bottom face portion for receiving an inner peripheral face of the coil trunk and a pair of side face portions erected from both sides of the bottom face portion for receiving side faces of the coil trunk and is integrated to the slot in a state where front end portions of the pair of side face portions are opened to an outer side. In this case, when the slot insulator is integrated into the slot and thereafter, the coil trunk is inserted into the slot, the coil trunk can be prevented from interfering with opening edge portions (front edge portions of the side face portions). Thereby, the slot insulator can be prevented from being bitten in when the coil trunk is inserted and accordingly, a failure in inserting the coil trunk into the slot can be prevented.
According to a further aspect of the present invention, in respect of a coil bar integrated to an armature core, a lower layer coil trunk, an upper layer coil trunk and all coil arms are integrally formed. In this case, respective ends of the lower layer coil trunk and the upper layer coil trunk need not to connect to the corresponding arms and therefore, bonding portions can be reduced. Further, the coil bar is integrated to the armature core by inserting the lower layer coil trunk to a slot, thereafter, bending one coil arm to the side of the armature core, and inserting the upper layer coil trunk to another slot provided to space apart with a predetermined interval from the slot to which the lower layer coil trunk has been inserted in the peripheral direction of the armature core. In this way, after inserting the lower layer coil trunk to the slot, the one coil arm can be bent and the upper layer coil trunk can be inserted into the predetermined slot and therefore, compared with the case where a finished coil which has previously been formed into a shape after inserting the coil into a slot is integrated to an armature core, the operation of integrating the coil bar to the armature core is facilitated and the possibility of impairing the coil bar in inserting the upper layer coil trunk to the slot is also reduced.